You use the RegexStringValidatorAttribute to decorate a configuration property, which will instruct the .NET Framework to validate the property using the RegexStringValidator and pass to it the value of the decorating parameters.

You may apply RegexStringValidatorAttribute objects to property types only.

The following example shows how to decorate the properties of a custom ConfigurationSection object using the RegexStringValidatorAttribute object.

<ConfigurationProperty("alias2", _
DefaultValue:="alias.txt", _
IsRequired:=True, _
IsKey:=False), _
RegexStringValidator("\w+\S*")> _
Public Property Alias2() As String
    Get
        Return CStr(Me("alias2"))
    End Get
    Set(ByVal value As String)
        Me("alias2") = value
    End Set
End Property

[ConfigurationProperty("alias2", DefaultValue = "alias.txt",
    IsRequired = true, IsKey = false)]
[RegexStringValidator(@"\w+\S*")]
public string Alias2
{
    get
    {
        return (string)this["alias2"];
    }
    set
    {
        this["alias2"] = value;
    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

.NET Framework

Reference